1. Field of the Invention
The present invention relates to a surface fastener molded from synthetic resin and having first and second engaging parts each in the form of a single molded body, on the hook bed surface of which a large number of engaging elements are formed in rows, which is particularly suitable for adhering industrial materials.
2. Description of the Related Art
The most common surface fastener is the so called velvet type fastener about which a great deal is known. This consists of a combination of a male tape and a female tape. On the whole, the female engaging part consists of knitted or woven loops. When the male engaging part is knitted or woven, it consists of loops, parts of which have been cut to form hooks and when the male engaging part is formed from a single molded body, it consists of various shapes such as, for example, hook, mushroom or anchor shapes. Although, as described above, the knitted or woven loops in themselves have high engaging strength, the overall engaging strength of the female engaging part is weak. Moreover, the positioning ability and the durability of the female engaging part are not of a sufficient standard for applications in the field of industrial materials at present because the loops are too flexible.
The development of molded surface fasteners made from synthetic resin is disclosed in, for example, U.S. Pat. No. 2,499,898, Japanese Utility Model Laid-Open Publication No. Sho 52-71808 and Japanese Utility Model Laid-Open Publication No. Hei 2-127205. These single molded body surface fasteners can have male and female engaging parts both of which can be made from synthetic resin material, which gives a positioning ability and self adhesive strength which is of a remarkably high standard when compared to the knitted or woven female engaging parts described above.
However, either one of the male and female engaging parts in the surface fastener described above will have a basic mushroom shape. The engaging strength resulting from a construction involving this kind of mushroom shape is, of course, weak when compared to those involving hook shapes. Also, if this kind of surface fastener is often used, it will soon lose a great deal of both its engaging strength and its durability.